The basic formula for percentage increase or decrease

To calculate percentage change in Excel, subtract the old value from the new value, divide by the old value, and multiply by 100. The formula is: ((New Value - Old Value) / Old Value) * 100

If the result is positive, you have a percentage increase. If it is negative, you have a percentage decrease. For example, if a price went from $50 to $65, the calculation is ((65 - 50) / 50) * 100 = 30%, meaning a 30% increase.

In Excel, you can write this as a formula in any cell. If your old value is in cell A1 and your new value is in cell B1, you would type: =((B1-A1)/A1)*100

Key Takeaways

  • The percentage change formula divides the difference between new and old values by the old value, then multiplies by 100.
  • You can enter the formula directly into a cell or use cell references like =((B1-A1)/A1)*100 to calculate multiple rows at once.
  • Formatting the result as a percentage removes the need to multiply by 100, so you can use =((B1-A1)/A1) and format as percentage instead.
  • Copying the formula down a column lets you calculate percentage change for dozens of rows without retyping.
  • Negative results indicate a decrease; positive results indicate an increase.

Setting up your data in columns

Organize your data so the old value is in one column and the new value is in another. For example, put "Original Price" in column A and "New Price" in column B, with your numbers starting in row 2. This layout makes it easy to write one formula and copy it down to all your rows.

Leave column C empty for your percentage change results. Click on cell C2 and type your formula there. Once the formula is entered and working, you can copy it down to every other row in seconds.

Writing and copying the formula down

Click on cell C2 and type: =((B2-A2)/A2)*100 then press Enter. Excel calculates the result for that row.

To copy this formula to all rows below, click on C2 again, then click and drag the small square in the bottom-right corner of the cell down to the last row with data. Excel automatically adjusts the cell references (A2 becomes A3, B2 becomes B3, and so on) for each row. Alternatively, copy the cell with Ctrl+C, select the range where you want the formula, and paste with Ctrl+V.

Using percentage formatting instead of multiplying by 100

You can simplify the formula by removing the *100 at the end and letting Excel's formatting do the work. Type: =((B2-A2)/A2) instead.

After entering the formula, select the cell or column of results. Right-click and choose "Format Cells", then select "Percentage" from the Category list. Excel multiplies the decimal by 100 and adds the % symbol automatically. This method is cleaner and easier to read in your spreadsheet.

Handling zero and negative starting values

If your old value (the denominator) is zero, Excel shows a #DIV/0! error because you cannot divide by zero. This happens when you are measuring change from a starting point of zero, which does not have a meaningful percentage. In these cases, you may need to note the change differently or exclude that row from your calculation.

If your old value is negative, the formula still works mathematically, but the result can be confusing. For example, if a value goes from -10 to 10, the percentage change is 200%, which is technically correct but may not match how you want to describe the change. Check your data to make sure negative values make sense for your purpose.

Calculating percentage increase versus percentage decrease

The same formula works for both increases and decreases. When the new value is larger than the old value, the result is positive (an increase). When the new value is smaller, the result is negative (a decrease).

If you want to display decreases without the minus sign, you can use the ABS function to show the absolute value: =ABS((B2-A2)/A2)*100 This removes the negative sign but still shows you the magnitude of change. Use this only if your context makes it clear whether you are talking about an increase or decrease.

Common mistakes to avoid

The most common error is reversing the order of subtraction. Always subtract the old value from the new value, not the other way around. If you swap them, your increase becomes a decrease and vice versa.

Another mistake is forgetting to divide by the old value. Dividing by the new value instead gives you a completely different number that does not represent percentage change. Always divide by the starting point, not the ending point. Also check that you are using the correct cells in your formula — a typo like =((B2-A1)/A2)*100 will give wrong results because you mixed rows.

Frequently Asked Questions

What is the difference between percentage change and percentage point change?

Percentage change is what this formula calculates — the relative shift from one value to another. Percentage point change is the simple difference between two percentages. For example, if unemployment goes from 5% to 8%, that is a 3 percentage point increase, but a 60% percentage change (because 8 is 60% higher than 5).

Can I use this formula for values that are already percentages?

Yes, the formula works the same way. If a rate goes from 5% to 8%, you enter 5 and 8 as your values and calculate ((8-5)/5)*100 = 60%. This tells you the percentage increased by 60%, not that it went up 3 percentage points.

How do I show only two decimal places in my percentage result?

Right-click the cell with your result, choose "Format Cells", select "Percentage", and set the decimal places to 2. Excel then displays your result as something like 30.25% instead of 30.2500%. You can adjust the number of decimal places to whatever you need.

What if I want to calculate percentage change for hundreds of rows?

Write the formula in the first data row, then select that cell and copy it. Select the entire range where you want the formula (you can click the first cell, hold Shift, and click the last cell), then paste. Excel fills every cell with the formula, adjusting the row numbers automatically for each one.

Can I use this formula to calculate a percentage of a total?

No, this formula is specifically for percentage change between two values. To calculate what percentage one number is of a total, use a different formula: =(Part/Total)*100. For example, if 25 people out of 100 attended, that is (25/100)*100 = 25%.